“This 14-hour closure has the potential to create a massive traffic jam of up to three hours if motorists do not heed the warnings to stay away,” Lauri Berman, Caltrans’ San Diego district director, said in a recent news release. “Once again, it is important that motorists avoid this area at all costs or risk being stuck in long traffic delays.”

Berman urged motorists nearby to stay home during the closure. But if they cannot avoid driving in the area, Caltrans suggests north-south drivers take State Route 125 as a detour. That freeway turns into the South Bay Expressway toll road south of Route 94.

The toll road will be free for all drivers while I-805 is closed, according to Caltrans.

Interstate 5 is also suggested as a detour, though officials said that freeway may see heavy spill-over traffic.

Though Caltrans maps show it will be closed, the stretch of I-805 from the border to Route 905 will technically be open, said Ramon Martinez, an agency project manager. However, Caltrans is strongly encouraging all motorists to avoid driving anywhere near the area. He said that includes the I-805 interchange with San Ysidro Boulevard, which will be open.

Martinez added that traffic headed across the border with Mexico into the United States will be diverted away from I-805 on Sunday and onto I-5.

I-805 won’t be the only Southern California freeway shut down this weekend. Nearly four miles of southbound 405 in Orange County will be closed for 20 hours starting at 9 p.m. Saturday through 5 p.m. on Sunday. That blockade is being called the “Bridge Bash,” and will run between Westminster and Long Beach. And, yes, it’s also needed to tear down a bridge.

The I-805 project is the second to shut down a San Diego County freeway in less than a month. Caltrans closed part of southbound Interstate 15 near Poway in late July to fix a drainage problem. The agency and one driver who chronicled his experience said the freeway backup wasn’t too bad, especially since the I-15 express lanes were free and open as a detour. Surface streets near the closure did experience delays, Caltrans reported.

Traffic weary residents can rejoice in this bit of good news: There are no more major freeway closures set for San Diego County this year.